Getting sinew in the UK requires more leg work than it does in the US...there are no nice archery supply places to buy it from, and hunting is very different.
In Britain also, there is much less of a connection to horse archery, either native American, or Eurasian, hence no cultural connection to sinew backed bows. Most archers in this country who develope a desire to shoot a wooden bow go with some variant of the D-section longbow, and a distressing number go with bows laminated from various tropical hardwoods.
I have only ever seen one sinewed bow and unless you shoot a short bow it seemed like a lot of trouble. I guess that if I got my hands on some osage, or juniper, and enough sinew, I would like to try making one, but if all I have is ash, and lumber yard timber, I will stick with plant fibre backing, or no backing at all.